Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) common language definition of gout

Molecular mechanisms of urate transport by the native human URAT1 and its inhibition by anti-gout drugs

Gout, a common and painful disease, stems from hyperuricemia, where elevated blood urate levels lead to urate crystal formation in joints and kidneys. The human urate transporter 1 (hURAT1) plays a critical role in urate homeostasis by facilitating urate reabsorption in the renal proximal tubule, making it a key target for gout therapy. Pharmacological inhibition of hURAT1 with drugs such as dotinurad, benzbromarone, lesinurad, and verinurad promotes urate excretion and alleviates gout symptoms. Here, we present cryo-electron microscopy structures of native hURAT1 bound with these anti-gout drugs in the inward-open state, and with urate in inward-open, outward-open, and occluded states. Complemented by mutagenesis and cell-based assays, these structures reveal the mechanisms of urate reabsorption and hURAT1 inhibition. Our findings elucidate the molecular basis of urate transport and anti-gout medication action and provide a structural framework for the rational design of next-generation therapies for hyperuricemia and gout.

Global, regional, and national burden of gout, 1990-2020, and projections to 2050: a systematic analysis of the Global Burden of Disease Study 2021

BACKGROUND

Gout is an inflammatory arthritis manifesting as acute episodes of severe joint pain and swelling, which can progress to chronic tophaceous or chronic erosive gout, or both. Here, we present the most up-to-date global, regional, and national estimates for prevalence and years lived with disability (YLDs) due to gout by sex, age, and location from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021, as well as forecasted prevalence to 2050.

METHODS

Gout prevalence and YLDs from 1990 to 2020 were estimated by drawing on population-based data from 35 countries and claims data from the USA and Taiwan (province of China). Nested Bayesian meta-regression models were used to estimate prevalence and YLDs due to gout by age, sex, and location. Prevalence was forecast to 2050 with a mixed-effects model.

FINDINGS

In 2020, 55·8 million (95% uncertainty interval 44·4-69·8) people globally had gout, with an age-standardised prevalence of 659·3 (525·4-822·3) per 100 000, an increase of 22·5% (20·9-24·2) since 1990. Globally, the prevalence of gout in 2020 was 3·26 (3·11-3·39) times higher in males than in females and increased with age. The total number of prevalent cases of gout is estimated to reach 95·8 million (81·1-116) in 2050, with population growth being the largest contributor to this increase and only a very small contribution from the forecasted change in gout prevalence. Age-standardised gout prevalence in 2050 is forecast to be 667 (531-830) per 100 000 population. The global age-standardised YLD rate of gout was 20·5 (14·4-28·2) per 100 000 population in 2020. High BMI accounted for 34·3% (27·7-40·6) of YLDs due to gout and kidney dysfunction accounted for 11·8% (9·3-14·2).

INTERPRETATION

Our forecasting model estimates that the number of individuals with gout will increase by more than 70% from 2020 to 2050, primarily due to population growth and ageing. With the association between gout disability and high BMI, dietary and lifestyle modifications focusing on bodyweight reduction are needed at the population level to reduce the burden of gout along with access to interventions to prevent and control flares. Despite the rigour of the standardised GBD methodology and modelling, in many countries, particularly low-income and middle-income countries, estimates are based on modelled rather than primary data and are also lacking severity and disability estimates. We strongly encourage the collection of these data to be included in future GBD iterations.

FUNDING

Bill & Melinda Gates Foundation and the Global Alliance for Musculoskeletal Health.

Identification of Anastatica hierochuntica L. Methanolic-Leaf-Extract-Derived Metabolites Exhibiting Xanthine Oxidase Inhibitory Activities: In Vitro and In Silico Approaches

There is a growing interest in the discovery of novel xanthine oxidase inhibitors for gout prevention and treatment with fewer side effects. This study aimed to identify the xanthine oxidase (XO) inhibitory potential and drug-likeness of the metabolites present in the methanolic leaf extract of Anastatica (A.) hierochuntica L. using in vitro and in silico models. The extract-derived metabolites were identified by liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry (LC-QTOF-MS). Molecular docking predicted the XO inhibitory activity of the identified metabolites and validated the best scored in vitro XO inhibitory activities for experimental verification, as well as predictions of their anticancer, pharmacokinetic, and toxic properties; oral bioavailability; and endocrine disruption using SwissADMET, PASS, ProTox-II, and Endocrine Disruptome web servers. A total of 12 metabolites, with a majority of flavonoids, were identified. Rutin, quercetin, and luteolin flavonoids demonstrated the highest ranked docking scores of -12.39, -11.15, and -10.43, respectively, while the half-maximal inhibitory concentration (IC50) values of these metabolites against XO activity were 11.35 µM, 11.1 µM, and 21.58 µM, respectively. In addition, SwissADMET generated data related to the physicochemical properties and drug-likeness of the metabolites. Similarly, the PASS, ProTox-II, and Endocrine Disruptome prediction models stated the safe and potential use of these natural compounds. However, in vivo studies are necessary to support the development of the prominent and promising therapeutic use of A. hierochuntica methanolic-leaf-extract-derived metabolites as XO inhibitors for the prevention and treatment of hyperuricemic and gout patients. Furthermore, the predicted findings of the present study open a new paradigm for these extract-derived metabolites by revealing novel oncogenic targets for the potential treatment of human malignancies.

Comparative Cardiovascular Risks of Febuxostat and Allopurinol in Patients with Diabetes Mellitus and Chronic Kidney Disease

BACKGROUND Hyperuricemia, which is common in chronic kidney disease and diabetes mellitus patients, raises health concerns. Febuxostat, a first-line urate-lowering agent, prompts cardiovascular risk questions, especially in high-risk patients. This study compared the effects of febuxostat and allopurinol on cardiovascular risk in diabetes mellitus and chronic kidney disease patients. MATERIAL AND METHODS This retrospective observational cohort study, conducted using Taiwan's National Health Insurance Research Database, focused on patients diagnosed with chronic kidney disease and diabetes between January 2012 and December 2017. The study population was divided into 2 groups: allopurinol users (n=12 901) and febuxostat users (n=2997). We performed 1: 1 propensity score matching, resulting in subgroups of 2997 patients each. The primary outcomes were assessed using a competing risk model, estimating hazard ratios (HR) for long-term outcomes, including the risks of all-cause hospitalization, hospitalization for heart failure, and hospitalization for cardiovascular interventions. RESULTS Febuxostat users, compared to allopurinol users, had higher all-cause hospitalization (HR: 1.33; 95% confidence interval [CI]: 1.25 to 1.42; P<.001), hospitalization for heart failure (HR: 1.62; 95% CI: 1.43 to 1.83; P<.001), and hospitalization for cardiovascular interventions (HR: 1.51; 95% CI: 1.32 to 1.74; P<.001). Moreover, the adverse effects of febuxostat on cardiac health were consistent across most subgroups. CONCLUSIONS Use of febuxostat in patients with diabetes mellitus and chronic kidney disease is associated with higher cardiovascular risks compared to allopurinol. Prudent evaluation is essential when recommending febuxostat for this at-risk group.

Miliarial-type gout in association with chronic use of glucocorticoids

A 59-year-old male patient with long-standing tophaceous gout (more than 30 years) characterized by polyarticular involvement and recurrent disseminated tophi formation; his past medical history is relevant for poor adherence to urate-lowering medications, as well as persistent use of self-prescribed systemic glucocorticoids. Despite achieving therapeutic goals for serum uric acid levels, new tophi formation with an intradermal location in the form of "miliarial-type gout" was documented. Due to functional limitations, the patient underwent surgical resection of the olecranon bursa. This case illustrates a widespread and recurrent tophi formation associated with long-standing gout and regular and sustained glucocorticoid use, despite an adequate disease control based on serum urate levels and involving an intradermal location of tophi presenting as "miliarial-type" lesions. In addition, the coexistence of urate and cholesterol crystal deposition disease in olecranon gouty bursitis is presented. Finally, a sonographic extended field of view of lesions distributed along the patient's extremities is presented as a novel characterization of this condition.

"Dialogue Between Franklin and the Gout" Reexamined

Benjamin Franklin, one of the founding fathers of the United States, was not just a politician and a political philosopher but an inventor with a scientific temperament. He was overweight and likely suffered from the consequences of metabolic syndrome including gout. He woke up with a gout attack on October 22, 1780 and wrote the "Dialogue Between Franklin and the Gout." His observations on the risk factors for gout are re-examined in the modern context 243 years later.

The Independent Value of Neutrophil to Lymphocyte Ratio in Gouty Arthritis: A Narrative Review

Since the incidence of gouty arthritis (GA) exhibits yearly increases, accurate assessment and early treatment have significant values for improving disease conditions and monitoring prognosis. Neutrophil to lymphocyte ratio (NLR) is a common indicator in blood routine, which has the characteristics of easy access and low cost. In recent years, NLR has been proven to be an effective indicator for guiding the diagnosis, treatment, and prognosis of various diseases. Moreover, NLR has varying degrees of relationship with various inflammatory biomarkers, which can affect and reflect the inflammatory response in the body. This paper reviews the independent value of NLR for GA and its underlying molecular pathological mechanisms, intending to contribute to the further application of NLR.